Smoky sausage casserole

Name: Smoky sausage casserole
Ingredients: 1 tbsp olive oil; 1 onion, finely chopped; 1 garlic clove, crushed; 1 large celery stick, finely chopped; 2 peppers (any colour), cut into chunks; pack 6 pork sausage (about 400g/14oz); 1 tsp sweet smoked paprika; ½ tsp ground cumin; ½ tsp chilli flakes; 2 x 400g cans chopped tomatoes; 400g can cannellini beans, drained; 250g bag spinach (or use the same quantity as frozen); 2 tbsp fresh breadcrumbs (or frozen with herbs)